/*
 * Copyright (C) 2015 Microchip Technology
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/microchipphy.h>
#include <linux/delay.h>

#define DRIVER_AUTHOR   "WOOJUNG HUH <woojung.huh@microchip.com>"
#define DRIVER_DESC     "Microchip LAN88XX PHY driver"

struct lan88xx_priv {
        int     chip_id;
        int     chip_rev;
        __u32   wolopts;
};

static int lan88xx_read_page(struct phy_device *phydev)
{
        return __phy_read(phydev, LAN88XX_EXT_PAGE_ACCESS);
}

static int lan88xx_write_page(struct phy_device *phydev, int page)
{
        return __phy_write(phydev, LAN88XX_EXT_PAGE_ACCESS, page);
}

static int lan88xx_phy_config_intr(struct phy_device *phydev)
{
        int rc;

        if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
                /* unmask all source and clear them before enable */
                rc = phy_write(phydev, LAN88XX_INT_MASK, 0x7FFF);
                rc = phy_read(phydev, LAN88XX_INT_STS);
                rc = phy_write(phydev, LAN88XX_INT_MASK,
                               LAN88XX_INT_MASK_MDINTPIN_EN_ |
                               LAN88XX_INT_MASK_LINK_CHANGE_);
        } else {
                rc = phy_write(phydev, LAN88XX_INT_MASK, 0);
        }

        return rc < 0 ? rc : 0;
}

static int lan88xx_phy_ack_interrupt(struct phy_device *phydev)
{
        int rc = phy_read(phydev, LAN88XX_INT_STS);

        return rc < 0 ? rc : 0;
}

static int lan88xx_suspend(struct phy_device *phydev)
{
        struct lan88xx_priv *priv = phydev->priv;

        /* do not power down PHY when WOL is enabled */
        if (!priv->wolopts)
                genphy_suspend(phydev);

        return 0;
}

static int lan88xx_TR_reg_set(struct phy_device *phydev, u16 regaddr,
                              u32 data)
{
        int val, save_page, ret = 0;
        u16 buf;

        /* Save current page */
        save_page = phy_save_page(phydev);
        if (save_page < 0) {
                pr_warn("Failed to get current page\n");
                goto err;
        }

        /* Switch to TR page */
        lan88xx_write_page(phydev, LAN88XX_EXT_PAGE_ACCESS_TR);

        ret = __phy_write(phydev, LAN88XX_EXT_PAGE_TR_LOW_DATA,
                          (data & 0xFFFF));
        if (ret < 0) {
                pr_warn("Failed to write TR low data\n");
                goto err;
        }

        ret = __phy_write(phydev, LAN88XX_EXT_PAGE_TR_HIGH_DATA,
                          (data & 0x00FF0000) >> 16);
        if (ret < 0) {
                pr_warn("Failed to write TR high data\n");
                goto err;
        }

        /* Config control bits [15:13] of register */
        buf = (regaddr & ~(0x3 << 13));/* Clr [14:13] to write data in reg */
        buf |= 0x8000; /* Set [15] to Packet transmit */

        ret = __phy_write(phydev, LAN88XX_EXT_PAGE_TR_CR, buf);
        if (ret < 0) {
                pr_warn("Failed to write data in reg\n");
                goto err;
        }

        usleep_range(1000, 2000);/* Wait for Data to be written */
        val = __phy_read(phydev, LAN88XX_EXT_PAGE_TR_CR);
        if (!(val & 0x8000))
                pr_warn("TR Register[0x%X] configuration failed\n", regaddr);
err:
        return phy_restore_page(phydev, save_page, ret);
}

static void lan88xx_config_TR_regs(struct phy_device *phydev)
{
        int err;

        /* Get access to Channel 0x1, Node 0xF , Register 0x01.
         * Write 24-bit value 0x12B00A to register. Setting MrvlTrFix1000Kf,
         * MrvlTrFix1000Kp, MasterEnableTR bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x0F82, 0x12B00A);
        if (err < 0)
                pr_warn("Failed to Set Register[0x0F82]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x06.
         * Write 24-bit value 0xD2C46F to register. Setting SSTrKf1000Slv,
         * SSTrKp1000Mas bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x168C, 0xD2C46F);
        if (err < 0)
                pr_warn("Failed to Set Register[0x168C]\n");

        /* Get access to Channel b'10, Node b'1111, Register 0x11.
         * Write 24-bit value 0x620 to register. Setting rem_upd_done_thresh
         * bits
         */
        err = lan88xx_TR_reg_set(phydev, 0x17A2, 0x620);
        if (err < 0)
                pr_warn("Failed to Set Register[0x17A2]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x10.
         * Write 24-bit value 0xEEFFDD to register. Setting
         * eee_TrKp1Long_1000, eee_TrKp2Long_1000, eee_TrKp3Long_1000,
         * eee_TrKp1Short_1000,eee_TrKp2Short_1000, eee_TrKp3Short_1000 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x16A0, 0xEEFFDD);
        if (err < 0)
                pr_warn("Failed to Set Register[0x16A0]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x13.
         * Write 24-bit value 0x071448 to register. Setting
         * slv_lpi_tr_tmr_val1, slv_lpi_tr_tmr_val2 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x16A6, 0x071448);
        if (err < 0)
                pr_warn("Failed to Set Register[0x16A6]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x12.
         * Write 24-bit value 0x13132F to register. Setting
         * slv_sigdet_timer_val1, slv_sigdet_timer_val2 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x16A4, 0x13132F);
        if (err < 0)
                pr_warn("Failed to Set Register[0x16A4]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x14.
         * Write 24-bit value 0x0 to register. Setting eee_3level_delay,
         * eee_TrKf_freeze_delay bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x16A8, 0x0);
        if (err < 0)
                pr_warn("Failed to Set Register[0x16A8]\n");

        /* Get access to Channel b'01, Node b'1111, Register 0x34.
         * Write 24-bit value 0x91B06C to register. Setting
         * FastMseSearchThreshLong1000, FastMseSearchThreshShort1000,
         * FastMseSearchUpdGain1000 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x0FE8, 0x91B06C);
        if (err < 0)
                pr_warn("Failed to Set Register[0x0FE8]\n");

        /* Get access to Channel b'01, Node b'1111, Register 0x3E.
         * Write 24-bit value 0xC0A028 to register. Setting
         * FastMseKp2ThreshLong1000, FastMseKp2ThreshShort1000,
         * FastMseKp2UpdGain1000, FastMseKp2ExitEn1000 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x0FFC, 0xC0A028);
        if (err < 0)
                pr_warn("Failed to Set Register[0x0FFC]\n");

        /* Get access to Channel b'01, Node b'1111, Register 0x35.
         * Write 24-bit value 0x041600 to register. Setting
         * FastMseSearchPhShNum1000, FastMseSearchClksPerPh1000,
         * FastMsePhChangeDelay1000 bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x0FEA, 0x041600);
        if (err < 0)
                pr_warn("Failed to Set Register[0x0FEA]\n");

        /* Get access to Channel b'10, Node b'1101, Register 0x03.
         * Write 24-bit value 0x000004 to register. Setting TrFreeze bits.
         */
        err = lan88xx_TR_reg_set(phydev, 0x1686, 0x000004);
        if (err < 0)
                pr_warn("Failed to Set Register[0x1686]\n");
}

static int lan88xx_probe(struct phy_device *phydev)
{
        struct device *dev = &phydev->mdio.dev;
        struct lan88xx_priv *priv;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->wolopts = 0;

        /* these values can be used to identify internal PHY */
        priv->chip_id = phy_read_mmd(phydev, 3, LAN88XX_MMD3_CHIP_ID);
        priv->chip_rev = phy_read_mmd(phydev, 3, LAN88XX_MMD3_CHIP_REV);

        phydev->priv = priv;

        return 0;
}

static void lan88xx_remove(struct phy_device *phydev)
{
        struct device *dev = &phydev->mdio.dev;
        struct lan88xx_priv *priv = phydev->priv;

        if (priv)
                devm_kfree(dev, priv);
}

static int lan88xx_set_wol(struct phy_device *phydev,
                           struct ethtool_wolinfo *wol)
{
        struct lan88xx_priv *priv = phydev->priv;

        priv->wolopts = wol->wolopts;

        return 0;
}

static void lan88xx_set_mdix(struct phy_device *phydev)
{
        int buf;
        int val;

        switch (phydev->mdix_ctrl) {
        case ETH_TP_MDI:
                val = LAN88XX_EXT_MODE_CTRL_MDI_;
                break;
        case ETH_TP_MDI_X:
                val = LAN88XX_EXT_MODE_CTRL_MDI_X_;
                break;
        case ETH_TP_MDI_AUTO:
                val = LAN88XX_EXT_MODE_CTRL_AUTO_MDIX_;
                break;
        default:
                return;
        }

        phy_write(phydev, LAN88XX_EXT_PAGE_ACCESS, LAN88XX_EXT_PAGE_SPACE_1);
        buf = phy_read(phydev, LAN88XX_EXT_MODE_CTRL);
        buf &= ~LAN88XX_EXT_MODE_CTRL_MDIX_MASK_;
        buf |= val;
        phy_write(phydev, LAN88XX_EXT_MODE_CTRL, buf);
        phy_write(phydev, LAN88XX_EXT_PAGE_ACCESS, LAN88XX_EXT_PAGE_SPACE_0);
}

static int lan88xx_config_init(struct phy_device *phydev)
{
        int val;

        genphy_config_init(phydev);
        /*Zerodetect delay enable */
        val = phy_read_mmd(phydev, MDIO_MMD_PCS,
                           PHY_ARDENNES_MMD_DEV_3_PHY_CFG);
        val |= PHY_ARDENNES_MMD_DEV_3_PHY_CFG_ZD_DLY_EN_;

        phy_write_mmd(phydev, MDIO_MMD_PCS, PHY_ARDENNES_MMD_DEV_3_PHY_CFG,
                      val);

        /* Config DSP registers */
        lan88xx_config_TR_regs(phydev);

        return 0;
}

static int lan88xx_config_aneg(struct phy_device *phydev)
{
        lan88xx_set_mdix(phydev);

        return genphy_config_aneg(phydev);
}

static struct phy_driver microchip_phy_driver[] = {
{
        .phy_id         = 0x0007c130,
        .phy_id_mask    = 0xfffffff0,
        .name           = "Microchip LAN88xx",

        .features       = PHY_GBIT_FEATURES,
        .flags          = PHY_HAS_INTERRUPT,

        .probe          = lan88xx_probe,
        .remove         = lan88xx_remove,

        .config_init    = lan88xx_config_init,
        .config_aneg    = lan88xx_config_aneg,

        .ack_interrupt  = lan88xx_phy_ack_interrupt,
        .config_intr    = lan88xx_phy_config_intr,

        .suspend        = lan88xx_suspend,
        .resume         = genphy_resume,
        .set_wol        = lan88xx_set_wol,
        .read_page      = lan88xx_read_page,
        .write_page     = lan88xx_write_page,
} };

module_phy_driver(microchip_phy_driver);

static struct mdio_device_id __maybe_unused microchip_tbl[] = {
        { 0x0007c130, 0xfffffff0 },
        { }
};

MODULE_DEVICE_TABLE(mdio, microchip_tbl);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");